Wander and wander sequences with a frequency below 10 Hz are used in the testing and measurement technologies to investigate the behavior of signal transmission circuits toward signals with very long periods. Thus, the use of wander or wander sequences in connection with synchronous digital signal transmission is required, as for example is indicated in the ITU-T Recommendation G.823 (03/93).
Up to this point, wander or wander sequences of the type cited above could only be produced through relatively high degrees of device engineering. In the process, function-modulating and frequency-modulating signal generators were used, which, however, led to the required wander amplitudes being issued at low clock frequencies and in all cases with a very high degree of circuitry.